1. Field of the Invention
The present invention relates to transfer arms to hold and move a container to a stage assembly, and more particularly, to such transfer arms having a self-clearing capability if unintended contact with the stage assembly or container occurs.
2. Description of the Prior Art
The prior art is replete with a variety of machines using various transfer mechanisms to move product through an assembly or manufacturing process. Empty containers supplied to the machine may undergo a variety of steps involving filling the container with product and the subsequent sealing and labeling steps. Following each step, the container may be discharged while a new container is moved into position to undergo the same step and repeat the cycle. Such machines are subject to stress and wear as they typically operate at high speeds. Often times malfunctions may occur which result in a shut-down of the machine, thus, reducing the effective rate at which product may be moved through an assembly or manufacturing process.
In typical prior art machines, empty containers may be positioned on and moved along a slide or track assembly by a transfer mechanism. The transfer mechanism may have a form adapted to receive the product and sufficient to retain the container during positioning. The transfer mechanism may move the empty container to a stage assembly to be filled with product. The stage assembly may lift the empty container to a product dispensing source to fill the container with product. The transfer mechanism may next move the filled container off of the stage assembly while at the some time moving the next empty container to be filled onto the stage assembly. The filled container moved off of the stage assembly may be positioned onto a conveyor slide for movement to the next step in the assembly process.
Unfortunately, typical prior art machines have many disadvantages. First, often times machines may be moving product through an assembly operation at a high rate of speed thus requiring a high degree of coordination between all moving elements of the assembly process. These moving elements may have an interaction which requires one moving element, such the transfer mechanism, to clear a position once delivering a container, before another moving element, such as the stage assembly, moves the container to a subsequent stage. If this coordination of moving elements is not perfect, the assembly operation may have to operate at a slower rate to avoid accidents. If an accident such as one moving element contacting another does occur, the assembly operation may have to be shut down to make necessary repairs. In either case the rate of assembly operation is not optimized.
Another disadvantage is that the containers may become stuck in the transfer mechanism resulting in a shut-down of the assembly process. This shutdown may be necessary to allow the container may be removed. The containers may become stuck as a result of ineffectively adapting different sized containers to the same assembly process. In addition, manufacturing tolerances may vary from one container to another, resulting in some containers being oversized and becoming stuck within the transfer mechanism. The containers may also leak or spill product, resulting in the container being stuck in an assembly mechanism. In either case the transfer mechanism may need to be shut down to allow the container to be removed.